CHT sensor anomaly

We removed the thermostat, it looks the problem solved.

@Bill - when the thermostat is CLOSED it blocks the flow to the radiator, no bypass only small flow through the thermostat

Logically all heads should be affected in the same way, but probably the front two was effected differently than the back two. But because we have one CHT sensor on the front one in back we were not able to compare them as front and back heads.

Also interesting if the data correct what was happening wirh the coolant in the head 2 near 130 degrees of Celsius - absolutely no sign of boiling or leak.

Using G12 mixture with distilled water, around 110 is the boiling.

Thanks for the help anyway. It was not new installation the plane was bought this way.

What Plane is this???

It is a bad idea to stop All (Most) coolant flow.

Typical thermostat system induce a bypass of the radiator and the thermostat closes that bypass when hot.

Full flow is always going somewhere.

Totally blocking all flow allows the heads to get overly hot with a thermostat that is not in the hot zone.

As you are seeing, thing are getting way out of control until the thermostat finally open.

Is it possible to increase the bypass through the thermostat?